1. Field of the Invention
The present invention relates to a tilting-pad thrust bearing and a rotary machine having the same.
2. Description of the Related Art
Typically, a steam turbine used in a thermal power plant or the like is connected to a power generator via a rotary shaft extending horizontally. To support the radial load of the shaft including its weight, multiple journal bearings are used. In a steam turbine, the hydrodynamic force fluctuates according to the rotational speed and load status of the rotary shaft, which causes the shaft to produce an axial load. For this reason, a thrust bearing is used to support the axial load of the shaft and prevent axial displacement of the shaft.
As thrust bearings having high load capabilities, tilting-pad thrust bearings are known. The tilting-pad thrust bearing disclosed in JP-2012-117608-A comprises: multiple pads swayably disposed on the outer circumferential side of a rotary shaft so as to face a thrust collar; and multiple oil feed sections disposed in spaces between the pads. While the thrust collar rotates, lubricating oil flows through the orifices of the oil feed sections into spaces between the thrust collar and the sliding surfaces of the pads to form oil films. These oil films help to support an axial load.